Abstract : The increasing of political and socio-economic changes strongly influences the budget balance of public organizations. They are constrained to move towards a more reactive and flexible organizational model. For public organizations, the challenge is to determine the best public-private hybridization, into a reticular structure, ensuring the economic performance of their services but also the creation of public value. These reorganizations present many pitfalls that are insufficiently addressed by public management literature. It analyzes management changes and gaps in the public sphere, but rarely suggests the methods and tools that support the forms of management it recommends. In this context, the aim of this thesis is to review the public management literature in order to bring a new perspective and propose the implementation of models, methods and tools of industrial engineering. Thus, we propose a meta-model and a methodological framework for the engineering of an extended organization. This proposal aims at controlling the complexity of a reticular structure without damaging the autonomy of the organizations (public and/or private) that compose it. The implementation of the proposed methodology is illustrated by a textbook case inspired by the clothing function of the French armies: the scenario of an outsourcing of this clothing function is studied taking into account its inclusion in a reticular structure.